Most conventional gas sensors rely on a single type of signal output: they provide either a qualitative visual warning or a quantitative electronic readout. This limits their deployment in critical areas like smart food packaging for quality control or wearable badges for industrial safety. For example, while current colour-changing polymer sensors can visually indicate meat spoilage, their response cannot be easily integrated into digital systems for remote, continuous logging. This project aims to bridge that gap by building a dual-mode sensor that reports gas exposure both visually and electronically in a single package. We are using Polydiacetylenes (PDAs), a class of polymers that change from blue to red when exposed to target gases like ammonia and amines, which are common byproducts of food decomposition. Because the structural shift that causes this colour change also alters electrical conductivity, we can theoretically measure both properties simultaneously. To make the polymer sufficiently conductive for a reliable electronic reading, you will engineer a composite material by integrating conductive charge-transfer-complex (CTC) crystals into the PDA matrix. You will take this concept from materials formulation to device prototyping. Your tasks will involve depositing these composite thin films onto interdigitated microelectrodes, exposing the sensors to target analytes, and simultaneously recording real-time electrical and optical data. This project provides hands-on experience in thin-film fabrication, microelectronics, and sensor characterisation, delivering proof-of-concept data for a new class of smart sensors.
School
Mechanical and Manufacturing Engineering
Research Area
Nanomaterials | Chemical sensors | Functional/responsive polymers | Sensor device fabrication | Materials chemistry
Suitable for recognition of Work Integrated Learning (industrial training)?
No
- Research environment
- Expected outcomes
- Supervisory team
- Reference material/links
The student will be co-supervised across two complementary areas of expertise: Prof. Rona Chandrawati's NanoFAM Laboratory (specialising in colorimetric nanosensors for food, health, and environmental monitoring) and Dr Mohamed Kilani's research focus on electrocrystallised nanomaterials and chemiresistive devices. The student will have hands-on access to materials synthesis facilities, patterned microelectrode platforms, and an automated gas-sensor testing bench equipped for controlled analyte concentration, humidity, and temperature. The combined supervisory team will provide day-to-day mentoring, ensuring a supportive cross-disciplinary environment ideal for a first research experience.
- Demonstration of a single PDA material transducing a gas signal both colorimetrically and electrically.
- Evaluation of whether PDA/CTC composite films improve the baseline chemiresistive response.
- Characterisation of a set of films with paired optical and electrical response data for a target analyte.
- Generation of preliminary results to seed a journal publication featuring the student as a contributor.
- Tjandra, Angie Davina, and Rona Chandrawati. "Polydiacetylene/copolymer sensors to detect lung cancer breath volatile organic compounds." RSC Applied Polymers 2.6 (2024): 1043-1056.
- Wang, Ren, et al. "Electrocrystallization of Copper 7, 7, 8, 8‐Tetracyanoquinodimethane Charge‐Transfer Complex on Flexible Substrates for Real‐Time Ammonia Gas Sensing." Advanced Sensor Research 4.3 (2025): 2400167.